But strictly speaking, atheistic materialism (even that of the Lokāyatas) is antagonistic to most principles of Hindu religion
That's not true. The differences are numerous
They show little to no interest in metaphysics. They are skeptical of "inferred" knowledge.
And they do not acknowledge the importance of the "invisible"
Because Plato and Aristotle always acknowledged the "soul". And the importance of the Invisible.
That stems from a penchant for the "invisible" - which is in its roots a religious outlook
A pure materialist would never engage in abstractions the way Plato did
There is no room for imagination. For idealizations. For ordering of "values"
Not a surprise that Lokāyatas had a very relaxed attitude towards all kinds of sensual pleasures
As that is not based on the "observed" reality
It is not "objective" so to speak
"The enjoyment of heaven lies in eating delicious food, keeping company of young women, using fine clothes, perfumes, garlands, sandal paste... while moksha is death which is cessation of life-breath..."
(Contd...)
A fool wears himself out by penances and fasts. Chastity and other such ordinances are laid down by clever weaklings"
Period.
The Charvaka authors are closer in spirit to Michel Foucault than any Hindu thinker in India.
Even several Christian theologians are less distant to us than Charvakas (though this may not go down well with parts of H-Right)